The victim suffered a bleed to the brain and was left with life-changing injuries.
At the Old Bailey, Mrs Justice McGowan said Bravery intended to kill and "almost killed that six-year-old boy".
"That little boy has suffered permanent and life-changing injury," the judge said in her sentencing remarks after Bravery had admitted attempted murder.
"You went to the viewing platform, looked around and spotted the victim and his family and went to the boy and threw him over the railing.
"The fear he must have experienced and the horror his parents felt are beyond imagination.
"What you did on the day of this offence prove you are a grave danger to the public. You planned this and appeared to revel in the notoriety."
On 4 August Bravery made his way to the Tate Modern's viewing balcony and the court heard CCTV footage showed him following young children and looking over railings.
Further video showed the victim - who had been visiting London from France - skipping ahead of his family along the platform towards Bravery.
Prosecutor Deanna Heer said: "The defendant scooped him up and, without any hesitation, carried him straight to the railings and threw him over."
The boy "fell head-first towards the ground", landing on a fifth-floor balcony below, she added.
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The victim survived the 100ft (30m) fall, but suffered life-changing injuries including a bleed on the brain and multiple broken bones. He remains in a wheelchair.
He was moved to a hospital in France in September but will require round-the-clock care support until at least 2022.
In mitigation Bravery's defence barrister Pippa McAtasney QC said at the time of the attack the teenager had been in the care of Hammersmith and Fulham Council.
The court heard Bravery had a history of lashing out at staff, but despite this he was allowed to leave home unsupervised for up to four hours at a time.
She said letters from his parents revealed to the court that Bravery was diagnosed with autism and "is a loved child".
"Both parents strived to improve the quality of his life and a secured and managed environment for their son," she said.
"They had no inclination their son would commit such a shocking crime. Those responsible for his care never communicated the contents of the shocking, prophetic recording that was revealed through the media."
In a victim impact statement taken in February, the boy's parents described Bravery's actions as "unspeakable".
"Words cannot express the horror and fear his actions have brought up on us," the couple said.
"Our son, who now, six months on, is wondering why he's in hospital.
"How can he not see in every stranger a potential 'villain' who could cause him immense pain and suffering?"
EMPTY cans, beer bottles and plastic bags were abandoned on beaches across the UK this morning, after Bournemouth declared a "major incident" yesterday.
Beach clean teams in Tynemouth and Brighton were among those battling to clear beauty spots after thousands of Brits flocked to the coast for the hottest day of the year yesterday.
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Plastic bags were strewn across Bournemouth beach last nightCredit: Getty Images - Getty
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Beach clean-up teams battled to clear the area this morningCredit: w8media
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Piles of litter flooded Brighton beach this morning following yesterday's crowdsCredit: Alamy Live News
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An old chair and barbecue were discarded on Tynemouth beach in north east EnglandCredit: PA:Press Association
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A runner passes piles of litter on Brighton seafront this morning Credit: Alamy Live News
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Tens of thousands of Brits squeezed onto the beach at Bournemouth yesterdayCredit: Getty Images - Getty
In Bournemouth, roads leading to the coast were gridlocked, cars were dumped at the roadside and tons of litter was left strewn across the popular resort.
Bournemouth, Christchurch and Poole council said it had no choice but to declare a major incident and condemned the "irresponsible" behaviour of crowds, some of whom got involved in fights.
'IRRESPONSIBLE BEHAVIOUR'
But beach-goers still left their rubbish behind, with waste collections including deck chairs, bins and boxes of food.
Speaking from Bournemouth beach this morning, local MP Tobias Ellwood told BBC Breakfast: "This place was deluged and social distancing went out the window and that's why a major incident was declared, because the local authority and indeed the police couldn't cope."
"We need to learn from this and recognise that if we're going to be serious about tackling this pandemic then we need to be swifter in being able to provide support to local authorities who are unable to cope."
Hot spots like Brighton and Tynemouth were also packed yesterday, with beach-goers crammed in like sardines as police attempted to enforce social distancing.
Bins overflowed in Brighton while an old arm chair and tent were among the refuse in Tynemouth, north east of England.
Seagulls in Bournemouth were seen surrounding the litter as they scavenged for left over spoils.
On Thursday morning, Bournemouth beach teams collected 33 tonnes of rubbish from the stretch of coastline- and the figures are likely to have been similar today.
When asked about crowds gathering on beaches, Environment Secretary George Eustice told BBC Breakfast: "We just have to recognise yesterday was the hottest day of the year, incredibly hot, a lot of people had the same idea, they all went to the beach, and yes of course those scenes at Bournemouth are a matter for concern."
'POWER TO CLOSE BEACHES'
Meanwhile, Matt Hancock said the government had the power to close beaches if people ignored coronavirus rules.
In an interview with TalkRadio, Mr Hancock said: "We do have that power [to close beaches]. I am reluctant to use it because people have had a pretty tough lockdown and I want everybody to enjoy the sunshine.
"But the key is to do it with respect for the rules – stay with your household, stay a good distance from other households."
But he added that if there was a spike in the number of coronavirus cases "then we will take action".
Chief medical officer for England Professor Chris Whitty urged people to follow social distancing rules in the hot weather or risk causing a spike in coronavirus.
He wrote on Twitter: "Covid-19 has gone down due to the efforts of everyone but is still in general circulation.
"If we do not follow social distancing guidance then cases will rise again.
"Naturally people will want to enjoy the sun but we need to do so in a way that is safe for all."
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Litter bugs made little effort to put their rubbish in the bins provided at Brighton beachCredit: Alamy Live News
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Seagulls surrounded the waste on Bournemouth beach this morningCredit: w8media
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Deck chairs and bins were collected in the mass clean up Credit: w8media
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A worker piles rubbish into a bin bag on Bournemouth seafront this morningCredit: w8media
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Bins overflowed with rubbish on Bournemouth beachCredit: Simon Jones - The Sun
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A Bournemouth car park was left in tattersCredit: w8media
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In Brighton, piles of rubbish were left by binsCredit: London News Pictures
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Beach goers trashed the hotspot yesterday as temperatures soaredCredit: Getty Images - Getty
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Bins overflowed with beer cans and plastic bags Tynemouth beachCredit: PA:Press Association
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Tynemouth beach bins were filled to the brim, spilling out over the sandCredit: PA:Press Association
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A tent was seen on Tynemouth beach this morning as piles of rubbish filled the sandCredit: PA:Press Association
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Police at Brighton beach on ThursdayCredit: London News Pictures
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Police patrol the beach at Bournemouth Credit: Getty Images - Getty
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Brits enjoy the sunshine as they sunbathe and play in the sea on Bournemouth beachCredit: AFP or licensors
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Health Secretary Matt Hancock has said the Government has the power to shut down beaches if necessaryCredit: Bournemouth News
Last night, Downing Street warned the public that failure to adhere to social distancing on beaches could risk lockdown restrictions being reimposed.
They are due to be lifted on July 4.
The Prime Minister’s spokesman said: "The PM and the Government scientific and medical advisers have stressed the great importance of the public continuing to adhere to social distancing advice.
“It’s because of the public’s hard work that we’ve been able to bring the virus under control.
"If the rules don’t continue to be followed and the virus starts to spread exponentially again then we will look at having to reverse some of the easements that we have put in place.
"I don’t think anyone in the British public would want that to happen."
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A packed Bournemouth beach on the hottest day of the year so farCredit: w8media
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Piles of litter were gathered up on Tynemouth beach this morningCredit: PA:Press Association
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Cigarette packs, cans and bottles were strewn across the beach in BrightonCredit: Alamy Live News
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Empty beer bottles were left in the sandCredit: Simon Jones - The Sun
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An inflatable was abandoned in the sand on Bournemouth beachCredit: Simon Jones - The Sun
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A burned out barbecue was filled with beer cans on Tynemouth beach todayCredit: PA:Press Association
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Empty bottles were discarded on Brighton beach as the hotspot was flooded with crowds yesterdayCredit: London News Pictures
Two local Tory MPs branded the photos of packed Brits on the beach "obscene" and warned lives were being put in danger.
They called for extra police to be drafted in from other forces, tougher fines and even roadblocks to stop a repeat.
Council leader Vikki Slade said the resort was at breaking point with services "completely overstretched" by the sheer number of day-trippers.
She fumed: "We are absolutely appalled at the scenes witnessed on our beaches, particularly at Bournemouth and Sandbanks, in the last 24-48 hours.
"The irresponsible behaviour and actions of so many people is just shocking and our services are stretched to the absolute hilt trying to keep everyone safe.
"We have had no choice now but to declare a major incident and initiate an emergency response."
She had previously pleaded with sunbathers to stay away from the sweeping beach until social distancing rules are eased next Saturday.
A staggering 558 parking fines were issued in the area - the highest on record - as sunseekers struggled to find spaces and dumped their cars.
Dorset Assistant Chief Constable Sam de Reya said she had increased patrols along the beach - adding: "These are unprecedented times.
"The declaration of a major incident allows us to bring agencies together so we can take actions available to us to safeguard the public as much as possible.
"We are also reliant on people taking personal responsibility and strongly advise members of the public to think twice before heading to the area.
"Clearly we are still in a public health crisis and such a significant volume of people heading to one area places a further strain on emergency services resources.
"We would therefore stress again that we are asking people to please stay away from the area."
Bournemouth East MP Tobias Ellwood said he had been told by the police that about 500,000 visitors were in Dorset.
BEACH STRIFE
Beaches will be CLOSED if crowds ignore social distancing, Hancock warns
'UNACCEPTABLE ATTACKS'
Cambridge Uni backs academic who tweeted 'white lives don't matter'
COVID SURPRISE
Chilling video inside party that started virus cluster infecting 18 PEOPLE
BEACH BRAWLERS
Beach brawl as up to 200 sunbathers fight in front of horrified families
LOCKDOWN WARNING
PM warns of new lockdown after 500k cram onto beaches to enjoy 33C weather
BOILING POINT
Police officers targeted by mob for 2nd night running at illegal London rave
Temperatures soared to 33.4C at Heathrow Airport in west London on Thursday, making it the hottest day of the year so far.
In Brighton, police had to break up a fight on the promenade. The beach at Brighton was also packed with sun-seeking Brits.
Meanwhile, Prime Minister Boris Johnson is expected to announce on Friday the government's plans for air bridges, which will allow Britons to go on holiday to certain destinations without needing to quarantine for 14 days on their return, the Telegraph reported.
The first of these air bridges will allow holidaymakers to travel to "low-risk" European destinations, including France, Italy, Spain, Greece and Germany, from July 4.
But they added that now incidence is lower, they can look at ways to safely provide testing "in the heart of communities", in a way that is more easy and accessible to people.
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Police respond to a reports of fighting in Brighton Credit: London News Pictures
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People enjoy the hot weather in Brighton - but the government has warned they will shut beaches if people don't follow social distancing rulesCredit: Reuters
Brits in Bournemouth tell The Sun why they hit the beach despite coronavirus lockdown
Around 140 officers have been injured in London in the last three weeks, the Metropolitan Police commissioner has revealed.
Cressida Dick said the aggression shown to officers at recent illegal street parties in the capital has been "utterly unacceptable".
As well as a number of illegal street parties in recent days, there have been protests and counter-protests over the death of George Floyd in police custody in the US.
Police confront angry crowd in Brixton
Dame Cressida said the force has a "duty" to shut down unlawful music events during the coronavirus pandemic.
She was speaking after police officers came under attack for a second night in the capital.
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Officers were pelted with objects on Thursday night after being sent to break up a street party in Notting Hill, west London.
She said the Met were on the lookout for illegal parties after 22 officers were injured in violent scenes in Brixton, south London, on Wednesday evening.
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Dame Cressida said the force had "closed down several before they even got going", but condemned violence in Notting Hill as "completely, utterly unacceptable".
"These events are unlawful," she said.
Social distancing flouted in Notting Hill
"They shouldn't be happening and we have a duty to go and close them down and to disperse them.
"The local communities hate them, [it is] incredibly anti-social behaviour, very noisy during a pandemic and sometimes [there is] violence.
"For our officers who are simply doing their duty to be attacked is utterly unacceptable."
Home Secretary Priti Patel said the recent violence has been "appalling".
"The police have my full backing in tackling criminality & enforcing the law - criminals will face consequences," she wrote on Twitter.
Illegal party filmed in south London
"My best wishes go to those officers injured."
Scotland Yard said extra officers in protective gear had been dispatched to illegal raves and street parties around London on Thursday following the violent scenes in Brixton.
Dame Cressida said three officers sustained "really quite nasty injuries", adding: "It was a really really horrible incident for them to deal with, really vicious attacks by people using bottles, glasses and anything they could pick up."
She said the number of officers injured is now "heading up to 140-odd officers" in the last three weeks.
No officers were injured in the Notting Hill incident, which the Dame Cressida described as "very unacceptable behaviour but very much less serious".
Police called to illegal street party
Officers also attended another party on Streatham Common, south London.
Sky News reporter Noel Phillips attended the scene of a separate illegal rave in Tottenham, north London, where police officers congregated near a crowd of people outside a venue.
In a message to the public, Dame Cressida said: "Tell us about unlicensed music events. We will come and close them down.
"My message to my officers is that I will support you and I will do everything I can to ensure that you are able to do your job to your best ability and that you are well equipped."
The commissioner also voiced her concerns about the potential for more violence over the weekend.
She said London has experienced "a very difficult few weeks" as the COVID-19 lockdown has been eased and some people have "very high feelings" about issues such as Black Lives Matter.
Noting there have been both peaceful and violent protests, she said: "We have seen some large numbers of people completely flouting the health regulations, seeming not to care at all about their own or their families' health and wanting to have large parties.
"It is hot. Some people have drunk far too much. Some people are just angry and aggressive and some people are plain violent.
"We will be prepared this weekend. We have officers all over London working hard again to try to keep the peace and to protect our public from violence and disorder."
You’ve heard the jibes from left and right: Sir Keir Starmer, the lawyerly bore, knows no other way of doing politics than procedural tedium. In sacking Rebecca Long Bailey from the shadow cabinet yesterday, the Labour leader showed that he’s more than happy to dole out a more brutal kind of summary justice too.
At 10.02am yesterday Long Bailey, the sometime standard-bearer for the Corbynite left and shadow education secretary, punched six words into Twitter: “Maxine Peake is an absolute diamond.” The actress had given an interview to the Independent in which she offered forthright praise for Jeremy Corbyn, something she’s been doing more or less non-stop since 2017.
In the same piece, however, came the hair-raising suggestion that the Minneapolis policemen who killed George
